1. Field of the Invention
The present invention relates to touch panel technology field, more particularly to a touch panel display device and an array substrate thereof.
2. Description of the Prior Art
Compared to resistance touch panels, capacitive touch panels have better visibility, are capable of multi-touch, and possess greater usage flexibility. Therefore most touch panels in the market are capacitive touch panels.
Capacitive touch panels are an application of capacitive touch panel technology, which is a kind of touch panel technology realized by touch panel coordinates, attained by changes in capacitance, caused by fingers approaching capacitive touch panels. There are two important variables of capacitive touch panel technology. The first is the sensing capacitance between fingers and an upper sensing layer. The second is the parasitic capacitance between sensing layers or between a sensing layer and an optical panel. Generally speaking, the capacitance is determined by the ITO pattern relative to a driving electrode TX and a sensing electrode RX (i.e., the relative area of TX and RX), and the thickness as well as between the driving electrode TX and the sensing electrode RX. The value of capacitance has no relationship with circuit impedance.
In conventional technology, no matter if a touch panel integrated circuit (TP IC) and a source IC are put on a same flexible printed circuit (FPC) or on two different FPCs, the issue of unequal impedance values of wires in cabling between sensing electrodes and TP ICs are ignored. As shown in FIG. 1, surrounding the display area is a plurality of leads 12 connecting a touch detecting electrode 11. Regarding the position of the display panel, the leads 12 run in different lengths towards a TP IC 13, meaning different impedance values thereof, resulting in different levels of change in sensing signals of the touch detecting electrode 11 when passing through the leads 12. For example, two sensing signals, which in the beginning have a greater difference, turn to have a smaller difference after passing through two wires in different lengths. This may easily lead to false signal recognition, affecting sensitivity of touch panels.